Thirteen officials of central China's Henan Province have received penalties after a river was contaminated by arsenic, the local government said Sunday.

Liu Gaili, former deputy head of the environmental protection bureau of Minquan County, Shangqiu City, was given two years imprisonment with a three-year reprieve by a local court, according to Liu Huisheng, spokesman with the Shangqiu Municipal Government.

Twelve other officials, including a deputy head of the county, were either sacked from their posts or given party or administrative punishment, said Liu.

The Baogongmiao section of the Dasha River was found contaminated by arsenic on August 26, 2008. Water quality tests showed that the arsenic concentration was 899 times more than the safety standard.

An investigation showed that the Chengcheng Chemical Co. Ltd., a sulfuric acid plant, illegally dumped the toxic waste water into the river since late July, contaminating a total of 1,000 tons of water.

Experts with a water environment lab under the Chinese Academy of Sciences kept pouring a special chemical agent into the river since last August and successfully purified the water, said Dr. Wang Hongjie, who participated in the campaign.

Key sluices had been closed and dams were built to prevent the toxic spell from spreading into the neighboring Anhui Province.

Continuous tests conducted between November last year and March 26 this year showed the water remained safe and no residents or livestock along the river was poisoned, according to Liu.

The county's procuratorate filed a lawsuit against the manager and the production chief of the chemical company over environmental pollution on March 19.

The company had been closed because of the pollution.

Arsenic is a toxic chemical. If digested, it can lead to vomiting, diarrhea, kidney, liver and lung problems, and even death in extreme cases.